#define _CRT_SECURE_NO_WARNINGS 1
#include <string.h>
#include <stdio.h>
int main()
{
	char s[] = "12345Hello, World!";
	char letters[] = "abcdefghijklmnopqrstuvwxyz";
	size_t num = strcspn(s, letters);
	printf("%zu\n", num); 
	return 0;
}